Mounting substrate and light-emitting device using the same

Abstract

To provide a mounting substrate wherein insulation resistance of a metal substrate having an oxide film formed on the surface thereof is ensured, and light reflectance is improved by preventing a light-reflecting material contained in a reflection layer from diffusing into a surface of the metal substrate. A mounting substrate includes a metal substrate ( 21 ), and a surface layer section ( 22 ) formed on an upper surface of the metal substrate ( 21 ). The surface layer section ( 22 ) includes an oxide film layer ( 23 ) formed on a surface of the metal substrate ( 21 ), a barrier layer ( 24 ) formed on the oxide film layer ( 23 ), a reflection layer ( 25 ) formed on the barrier layer ( 24 ) and containing a light-reflecting material, and a protection film layer ( 26 ) formed on the reflection layer ( 25 ).

The invention claimed is: 
     
       1. A mounting substrate comprising:
 a metal substrate formed of an aluminum plate; and 
 a surface layer section formed on an upper surface of the metal substrate, 
 wherein the surface layer section includes:
 an oxide film layer comprising an alumite layer, the oxide film layer being formed on the upper surface of the metal substrate; 
 a barrier layer formed on the oxide film layer and containing at least one of titanium, nickel, ruthenium, palladium, tungsten, and platinum; 
 a reflection layer formed on the barrier layer and containing a light-reflecting material formed of silver; and 
 an insulating protection film layer formed on the reflection layer, and 
 
 wherein the insulating protection film layer is formed of a multilayer film including a light-transmitting resin film, a titanium oxide evaporated film, and a silicon oxide evaporated film. 
 
     
     
       2. The mounting substrate according to  claim 1 , wherein
 the barrier layer formed on the oxide film layer has a uniform thickness. 
 
     
     
       3. The mounting substrate according to  claim 1 , wherein
 the reflection layer is formed of a resin film made of a light transmitting resin containing silver. 
 
     
     
       4. The mounting substrate according to  claim 3 , wherein
 the silver is 90% or more in purity. 
 
     
     
       5. The mounting substrate according to  claim 1 , wherein
 the reflection layer is formed of a silver evaporated film. 
 
     
     
       6. The mounting substrate according to  claim 5 , wherein
 the silver is 90% or more in purity. 
 
     
     
       7. The mounting substrate according to  claim 1 , further comprising:
 a wiring substrate having a wiring pattern, the wiring substrate being formed on end portions of an upper surface of the surface layer section. 
 
     
     
       8. A light-emitting device comprising:
 the mounting substrate claimed in  claim 1 ; 
 at least one light-emitting diode element mounted on a surface of the mounting substrate; and 
 a light-transmitting resin body that seals the light-emitting diode element. 
 
     
     
       9. The light-emitting device according to  claim 8 , further comprising:
 a frame surrounding the light-transmitting resin body.